1. Field of the Invention
The present invention relates to a preliminary air conditioning system, and more particularly to a preliminary air conditioning system that charges a battery mounted in a motor vehicle with electric power that is supplied from a building and adjusts the temperature in the cabin of the motor vehicle before a passenger enters the motor vehicle.
2. Description of Related Art
In general, motor vehicles are equipped with a vehicle air conditioner that controls the temperature in the cabin to maintain the cabin in a comfortable air-conditioned state. Also, a vehicle air conditioner has been proposed which performs what is called preliminary air conditioning, i.e., controls the temperature in the cabin in a preset operation mode according to commands from a remote control or a timer setting before the passenger enters the motor vehicle.
In addition, hybrid vehicles that have a battery and are driven by an engine and a motor are becoming increasingly popular for reducing CO2 emissions which contribute to global warming. Likewise, electric vehicles powered by batteries also start to attract attention. Technology for charging the batteries mounted on such motor vehicles using electricity from houses has been proposed.
For example, Japanese Patent Application Publication No. 2009-134450 (JP-A-2009-134450) describes detecting the state of charge (SOC) of batteries when a plurality of vehicles are coupled to an external power source and determining estimated power consumption of each vehicle; calculating the necessary charging power for each vehicle based on the detected SOC and the estimated power consumption; detecting the time of start of use of each vehicle; and determining a charging schedule about the charging time and charging power for each vehicle based on the necessary amount of charge and the time of start of use to control the charging. The technology described in JP-A-2009-134450 relies on a timer to start preliminary air conditioning with a timer or the like to perform preliminary air conditioning before a passenger enters the vehicle at the planned time.
However, because the technology that is disclosed in JP-A-2009-134450 relies on a timer to start preliminary air conditioning, it is possible that preliminary air conditioning cannot be carried out appropriately if the motor vehicle is not used on schedule. Therefore, it still has room for improvement.